Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
hoc sach » hoc sinh, hoc cac, hoc anh
cham tuc » nham thuc, pham thuc, tham thuc
hieu van » thien van, lieu va, hieu ve
tinh vi » trinh vi, tinh voi, tinh va
va tinh » may tinh
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
tuc va » thuc va, truc va, tuc xa
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (hoc sach)) ky nang x hoi. ((hieu van) OR (hieu va)) cham tuc va tinh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (hoc sach)) ky nang x hoi. ((hieu van) OR (hieu va)) cham tuc va tinh vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (hoc sach)) ky nang x hoi. ((hieu van) OR (hieu va)) cham tuc va tinh vi cua viet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (hoc sach)) ky nang x hoi. ((hieu van) OR (hieu va)) cham tuc va tinh vi cua viet*.